Melanocortins are a family of regulatory peptides which are formed by post-translational processing of pro-hormone pro-opiomelanocortin. Melanocortins have been found in a wide variety of normal human tissues including the brain, adrenal, skin, testis, spleen, kidney, ovary, lung, thyroid, liver, colon, small intestine and pancreas. Melanocortin peptides have been shown to exhibit a wide variety of physiological activities including the control of behavior and memory, affecting neurotrophic and antipyretic properties, as well as affecting the modulation of the immune system, the control of the cardiovascular system, analgesia, thermoregulation and the release of other neurohumoral agents including prolactin, luteinizing hormone and biogenic amines. Five melanocortin receptors (MC-R) have been characterized to date: melanocyte-specific receptor (MC1-R), corticoadrenal-specific ACTH receptor (MC2-R), melacortin-3 (MC3-R), melanocortin-4 (MC4-R) and melanocortin-5 receptor (MC5-R). There has been great interest in melanocortin (MC-R) receptors as targets for the design of novel therapeutics to treat disorders of body weight such as obesity and cachexia. Both genetic and pharmacological evidence points toward central MC4-R receptors as the principal target. The current progress with receptor-selective agonists and antagonists evidences the therapeutic potential of melanocortin receptor activation, particularly MC4-R. Due to this therapeutic potential, there is a need of new formulations for this type of compounds, in particular a need of injection formulations.
Parenteral injection of a soluble active pharmaceutical ingredient in saline classically leads to a high value of the drug plasma peak concentration (Cmax) and an initial high variation rate of the plasmatic drug concentration that results in a short time (Tmax) to reach the maximal concentration Cmax, i.e. the burst effect. These two features of the pharmacokinetic (PK) profile can induce side effects, which may jeopardise the development and use of the drug.
A composition according to the present invention intends to reduce these drawbacks and allowed a sustained-release of the active ingredient over at least 3 hours.